llvm-6502/include/llvm/Analysis/IPModRef.h
2002-11-07 07:11:49 +00:00

229 lines
8.4 KiB
C++

//===- IPModRef.h - Compute IP Mod/Ref information --------------*- C++ -*-===//
//
// class IPModRef:
//
// class IPModRef is an interprocedural analysis pass that computes
// flow-insensitive IP Mod and Ref information for every function
// (the GMOD and GREF problems) and for every call site (MOD and REF).
//
// In practice, this needs to do NO real interprocedural work because
// all that is needed is done by the data structure analysis.
// This uses the top-down DS graph for a function and the bottom-up DS graph
// for each callee (including the Mod/Ref flags in the bottom-up graph)
// to compute the set of nodes that are Mod and Ref for the function and
// for each of its call sites.
//
//
// class FunctionModRefInfo:
//
// The results of IPModRef are encapsulated in the class FunctionModRefInfo.
// The results are stored as bit vectors: bit i represents node i
// in the TD DSGraph for the current function. (This node numbering is
// implemented by class FunctionModRefInfo.) Each FunctionModRefInfo
// includes:
// -- 2 bit vectors for the function (GMOD and GREF), and
// -- 2 bit vectors for each call site (MOD and REF).
//
//
// IPModRef vs. Alias Analysis for Clients:
//
// The IPModRef pass does not provide simpler query interfaces for specific
// LLVM values, instructions, or pointers because those results should be
// obtained through alias analysis (e.g., class DSAliasAnalysis).
// class IPModRef is primarily meant for other analysis passes that need to
// use Mod/Ref information efficiently for more complicated purposes;
// the bit-vector representations make propagation very efficient.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_IPMODREF_H
#define LLVM_ANALYSIS_IPMODREF_H
#include "llvm/Pass.h"
#include "Support/BitSetVector.h"
class Module;
class Function;
class CallInst;
class DSNode;
class DSGraph;
class DSNodeHandle;
class ModRefInfo; // Result of IP Mod/Ref for one entity
class FunctionModRefInfo; // ModRefInfo for a func and all calls in it
class IPModRef; // Pass that computes IP Mod/Ref info
//---------------------------------------------------------------------------
// class ModRefInfo
//
// Purpose:
// Representation of Mod/Ref information for a single function or callsite.
// This is represented as a pair of bit vectors, one each for Mod and Ref.
// Each bit vector is indexed by the node id of the DS graph node index.
//---------------------------------------------------------------------------
class ModRefInfo {
BitSetVector modNodeSet; // set of modified nodes
BitSetVector refNodeSet; // set of referenced nodes
public:
//
// Methods to construct ModRefInfo objects.
//
ModRefInfo(unsigned int numNodes)
: modNodeSet(numNodes),
refNodeSet(numNodes) { }
unsigned getSize() const {
assert(modNodeSet.size() == refNodeSet.size() &&
"Mod & Ref different size?");
return modNodeSet.size();
}
void setNodeIsMod (unsigned nodeId) { modNodeSet[nodeId] = true; }
void setNodeIsRef (unsigned nodeId) { refNodeSet[nodeId] = true; }
//
// Methods to query the mod/ref info
//
bool nodeIsMod (unsigned nodeId) const { return modNodeSet.test(nodeId); }
bool nodeIsRef (unsigned nodeId) const { return refNodeSet.test(nodeId); }
bool nodeIsKill(unsigned nodeId) const { return false; }
const BitSetVector& getModSet() const { return modNodeSet; }
BitSetVector& getModSet() { return modNodeSet; }
const BitSetVector& getRefSet() const { return refNodeSet; }
BitSetVector& getRefSet() { return refNodeSet; }
// Debugging support methods
void print(std::ostream &O) const;
void dump() const;
};
//----------------------------------------------------------------------------
// class FunctionModRefInfo
//
// Representation of the results of IP Mod/Ref analysis for a function
// and for each of the call sites within the function.
// Each of these are represented as bit vectors of size = the number of
// nodes in the top-dwon DS graph of the function. Nodes are identified by
// their nodeId, in the range [0 .. funcTDGraph.size()-1].
//----------------------------------------------------------------------------
class FunctionModRefInfo {
const Function& F; // The function
IPModRef& IPModRefObj; // The IPModRef Object owning this
const DSGraph& funcTDGraph; // Top-down DS graph for function
const DSGraph& funcLocalGraph; // Local DS graph for function
ModRefInfo funcModRefInfo; // ModRefInfo for the function body
std::map<const CallInst*, ModRefInfo*>
callSiteModRefInfo; // ModRefInfo for each callsite
std::map<const DSNode*, unsigned> NodeIds;
friend class IPModRef;
void computeModRef (const Function &func);
void computeModRef (const CallInst& callInst);
DSGraph *ResolveCallSiteModRefInfo(CallInst &CI,
std::map<const DSNode*, DSNodeHandle> &NodeMap);
public:
/* ctor */ FunctionModRefInfo (const Function& func,
IPModRef& IPModRefObj,
const DSGraph& tdg,
const DSGraph& ldg);
/* dtor */ ~FunctionModRefInfo ();
// Identify the function and its relevant DS graph
//
const Function& getFunction() const { return F; }
const DSGraph& getFuncGraph() const { return funcTDGraph; }
// Retrieve Mod/Ref results for a single call site and for the function body
//
const ModRefInfo* getModRefInfo (const Function& func) const {
return &funcModRefInfo;
}
const ModRefInfo* getModRefInfo (const CallInst& callInst) const {
std::map<const CallInst*, ModRefInfo*>::const_iterator I =
callSiteModRefInfo.find(&callInst);
return (I == callSiteModRefInfo.end())? NULL : I->second;
}
// Get the nodeIds used to index all Mod/Ref information for current function
//
unsigned getNodeId (const DSNode* node) const {
std::map<const DSNode*, unsigned>::const_iterator iter = NodeIds.find(node);
assert(iter == NodeIds.end() || iter->second < funcModRefInfo.getSize());
return (iter == NodeIds.end())? funcModRefInfo.getSize() : iter->second;
}
unsigned getNodeId (const Value* value) const;
// Debugging support methods
void print(std::ostream &O) const;
void dump() const;
};
//----------------------------------------------------------------------------
// class IPModRef
//
// Purpose:
// An interprocedural pass that computes IP Mod/Ref info for functions and
// for individual call sites.
//
// Given the DSGraph of a function, this class can be queried for
// a ModRefInfo object describing all the nodes in the DSGraph that are
// (a) modified, and (b) referenced during an execution of the function
// from an arbitrary callsite, or during an execution of a single call-site
// within the function.
//----------------------------------------------------------------------------
class IPModRef : public Pass {
std::map<const Function*, FunctionModRefInfo*> funcToModRefInfoMap;
Module* M;
FunctionModRefInfo& getFuncInfo(const Function& func,
bool computeIfMissing = false);
public:
IPModRef() : M(NULL) { }
~IPModRef() { }
// Driver function to run IP Mod/Ref on a Module.
// This initializes the module reference, and then computes IPModRef
// results immediately if demand-driven analysis was *not* specified.
//
virtual bool run(Module &M);
// Retrieve the Mod/Ref information for a single function
//
const FunctionModRefInfo& getFunctionModRefInfo(const Function& func) {
return getFuncInfo(func);
}
/// getBUDSGraph - This method returns the BU data structure graph for F
/// through the use of the BUDataStructures object.
///
const DSGraph &getBUDSGraph(const Function &F);
// Debugging support methods
//
void print(std::ostream &O) const;
void dump() const;
// Release memory held by this pass when the pass pipeline is done
//
virtual void releaseMemory();
// getAnalysisUsage - This pass requires top-down data structure graphs.
// It modifies nothing.
//
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
};
//===----------------------------------------------------------------------===//
#endif